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Need a lot of help with a subpump please...

Discussion in 'Electrical Engineering' started by noname, May 22, 2006.

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  1. noname

    noname Guest

    Hi. I hope someone here can help me. My father gave me an old submersible
    pump. A Gorman Rupp subpump. It's probably over 50 years old and it doesn't
    work anymore. I want to test and repair it if possible.

    It's a pump with no dry kill switch attached right next to the pump like we
    are seeing on the newer model ( no flowtation on/off swicht. It also a pump
    with a big disconnect box, in witch there are old electronic/electric
    parts: there is a electrical breaker , a relay , and a capacitor.

    This pump runs on 115vlt, 1 ph. It's a 2 hp pump and 28 amp

    I don't have much knowledge in electricity or electronic , but I would
    really like to see if this pump can work again. I know if was working fine
    when I was a kid. My father stored the pump and the switch box in an
    underground pit for many years and now it's all corroded and it's not

    Ok here is a picture of the pump:

    Now below is the picture of the switch box : Now in this switch box, the
    electricity comes in from the left side of the box , it goes into a relay
    and a capacitor , and comes out to the pump from the right side of the box.
    One thing that may trick you is regarding the electricity coming in, I know
    that usually one use the black and white wire for this but What they did
    here is used the black as live and the red as neutral. The white wire seen
    bended down is actually spare and not connected in any way.

    Also I'm no electrician and I'm not used to see a double breaker connected
    to a neutral.. ( remember what you are seeing is 115 vlt, not 220 vlt.) why
    is that?

    And here is the picture of the electrical diagram: this I'm sure will
    explain all the mistary of this pump, but unfortunately I can't understand
    or read this..

    now for the questions..

    How can I test the pump to know if it's fixable? I will tell you what I
    checked already: I check the breakers with my tester and they do not work
    anymore. So what I did was bypassing the breaker to see if the rest of the
    electronics work, and they don't. ( it's either the relay or the capacitor ,
    or both that don't work imo.)

    So what I did after this is connecting the 115vlt right on the pump's
    black and white wire ( I believe the red wire has to do with the capacitor,
    that's why I didn't check??? ) my 115 vlt was coming from a 15 amp braker .
    I saw a big spark when the live wire touched the black pump's wire , so I
    terminated the test right away as I thought It would trigger my home breaker
    ( remember my pump pulls 28 amps..)

    Would it make sense to hooked the pump into my oven plug ( 40amps). By
    hooking I mean bypassing all the electronics and connecting to the white and
    black wire of the pump itseft? Or no sense because if the relay and
    capacitor are not working, he pump won't start anyway?

    In order to buy new parts for the switch box, can someone with a brain give
    me some specs for a relay, a capacitor, and the discharge resistor (
    connected to the capacitor, see diagram )

    Also do one know if this pump is equipped with a kill switch if it ever
    runs dry? Can you guess it has or not form the diagram?

    Thanks for our time

    Thanks for you help

    you can reach me at

  2. Oppie

    Oppie Guest

    My opinion, If life is sweet and you want to be around much longer, take it
    to a electric motor rebuilder or someone acquainted with such equipment.
    Better safe than in oblivion...

    All you need is one bad gasket or seal to allow water into the motor guts.
    Once that happens, insulation resistance goes to hell and you get rampant
    corrosion. My gut feeling is that it is more likely worth more in scrap
    value for its copper and bronze content than anything else.
    Mike F likes this.
  3. Ben Miller

    Ben Miller Guest

    The electrical components are badly corroded, the motor winding is in
    unknown condition, and you know nothing about electricity. Please do not
    play with this, as it can kill you! The first step would be to megger the
    motor winding to determine the insulation condition. If you don't know what
    that means, throw the pump out and do NOT connect it to electrical power!


    Ben Miller
    Mike F likes this.
  4. noname

    noname Guest

    ok ....
    guys you are a bit hard on me.... ok I already knew sn oven runs on 230 volt
    , I forgot to point I would only take one faze of it...
    I might take your word for it and sent it to a specialist, or I might give
    it a shoot myself. I'm know I won't electrocute myself with this project.
    (43yom here...)I know a capacitor is a thing to treat with respect...
    if you guys would answer some of my questions, and some of you already did,
    I would greatly appreciate.
    this pump has a special value to me...
    thanks again
  5. TimPerry

    TimPerry Guest

    treat the project as if you were restoring a classic car or any other

    first disassemble the entire unit, taking photos at each step (so you can
    refer to them upon re-assembly.

    clean and refurb each piece. replace or machine new parts for one that seen
    to degraded to function. (yes i know you wont be able to just order
    replacement parts for this but that part of the challenge)

    mark or label each piece and store in a tackle box like container or parts
    bin with drawers. an electric etching tool will help.

    the motor rebuild i would not even attempt myself no matter how much
    sentimental value it held. i would send it out to a motor rebuild. almost
    certainly the rebuilder might urge you to replace it because it is so old or
    be hesitant about offering any warranty.

    for the pump you probably will end up relying on the "make a gasket" gels
    and goos.
    you might, with patience, cut your own gaskets out of a solid sheet of

    as part of the cleaning process i find an ordinary dishwasher with Cascade
    detergent come in handy. also brass brushes, dremmel tool with wire brush,
    steel wool and emmery paper all come in handy. add a little oven cleaner
    powder (Zud) and whatever other cleaners are handy (simple green, orange
    blast engine cleaner).

    whenever you finally decide to test the rebuilt unit please incorporate the
    use of a GFI circuit breaker. if it trips you have a problem in the unit.
    fix the problem. do not bypass the GFI. if you ever place it in service
    power it through a GFI.

    the guys are "a bit hard" on you because they, like me, get asked questions
    similar to this in person time to time. when replying face to face, or even
    on the phone i is easier to convey earnest conviction. many probably have
    worked "under the gun" trying to restore aging equipment still in use in
    industry. please believe me when i advise that "it aint gonna be easy, fast,
    or cheap"
  6. YD

    YD Guest

    <snip all the rest>

    Chiming in with all the others, don't bother. I suppose it's a bit of
    nostalgia but by the description of it the best you can do is fixing up
    the appearance and use as a decorative piece.

    To get it back to working condition you'll have to consult a pro and
    probably spend much more than it's really worth, certainly more than a
    new pump would cost you.

    - YD.
  7. Oppie

    Oppie Guest

    Sorry if I was unnecessarily hard on you. Something of this power level,
    submersible yet, is not recommended for a first project. Perhaps, get your
    feet wet on something else (and use a Ground Fault Interrupter).
  8. noname

    noname Guest

    ok thanks guys. I appreciate your help. I can deal with simple things in
    electricity, like last year , I changed the electrical panel in my house for
    a bigger one, and I built a few PC... but as far a making calculations for
    knowing what size capacitor , etc etc, that I'm in the dark...
    I will keep in mind SAFETY if I ever play the technician...I understood it
    won't be fast, cheap and easy....

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